-VPN now works with IPSEC. -Cortana is great for setting notifications, I love location based ones :) -Tile folders are great for tidying up your screen. -Quiet time.... No more emails in the middle of the night beeping!

I had the preview on my HTC 8X, Lumia 920 and now on my Lumia 930. No problems at all. All you need to do is install the app, sign in, accept the terms and check for updates. The terms say you can't go back once you update, but if you're using a Lumia, there is the Nokia recovery tool. Not that you will want to go back!